Anatomy Block 2

In fetal circulation there are 3 shunts. Name and function?

Answer:

Ductus veinosus- connects umbilical vein to the left hepatic vein to get oxygenated blood into the right atrium. Ductus arteriosus: connects pulmonary trunk to descending aorta to get oxygenated blood to lower body. Foramen Ovale: Connects Left and Right atrium so oxygenated blood can pass through left ventricle and enter aorta.

Pulmonary trunk stenosis leads to hypertrophy of right ventricle and rupture of the septum. This causes a right to left shunt which begins to pour deoxygenated blood into the left ventricle and through an overriding aorta which contains deoxygenated blood and causes cyanosis.

Stenosis of the descending aorta which causes high pressure in the upper limbs and more blood anastamosis from the intercoastal arteries to the thorasic artery and descending aorta, which causes rib notching due to the pressure.

Starting in the mucosa of the bronchi, it leads to coughing and hemoptysis, and metastisizes to the thorasic lymph node. From there it spreads everywhere. At the apex of the lung its referred to as a pancoast tumor and can lead to thorasic outlet syndrome.

A pancoast tumor may begin to compress the lower trunk of the brachial plexus (c8-T1) and the subclavian artery. It results in pain down the medial forearm and hand and can cause atrophy of the intrinsic hand muscles.